, cities and towns, homes and businesses all depend upon one basic resource. modern civilization and life itself would be impossible without it. woman: okay, so today, we're going to look at how do we get our water? narrator: and today, it's a matter of simply turning on the tap. so often, we forget about the value of water. water is a commodity that is essential to life. 100 years ago, it would have been hard to imagine turning on the tap water. and now, it's an expectation. narrator: over 300 million people live in the united states. and each person uses an average of 100 gallons of water every day. man: what it takes to actually make clean water is somewhat a mystery to most customers. woman: so how does water get from the river into your house, or here at school? woman: somebody has to bring that water to us, and somebody has to take it away when we're finished with it. man: the water infrastructure is vital for disease protection, fire protection, basic sanitation, economic development, and for our quality of life. man: you just can't visualize all the assets that are under our feet.